Namespace confusion: No declaration matches 'namespace::object::function'

Question

I befriended a constructor of a class priv by referencing it with the priv::-scope resolution from another class (notices), thinking that it would find the class object which resided in the same namespace. Turns out it doesnt and yelds a couple of other errors. What am I missing?

Errors:

In file included from C:/dev/test-cpp/components/fsm/include/notices.hpp:3,
                 from C:\dev\test-cpp\components\fsm\fsm.cpp:1:
C:/dev/test-cpp/components/fsm/include/priv.hpp:11:20: error: 'notices' does not name a type
   11 |         priv(const notices&);
      |                    ^~~~~~~
C:\dev\test-cpp\components\fsm\fsm.cpp:31:5: error: no declaration matches 'fsm::priv::priv(const fsm::notices&)'
   31 |     priv::priv(const notices& nos)
      |     ^~~~
In file included from C:/dev/test-cpp/components/fsm/include/notices.hpp:3,
                 from C:\dev\test-cpp\components\fsm\fsm.cpp:1:
C:/dev/test-cpp/components/fsm/include/priv.hpp:8:11: note: candidates are: 'constexpr fsm::priv::priv(fsm::priv&&)'
    8 |     class priv
      |           ^~~~
C:/dev/test-cpp/components/fsm/include/priv.hpp:8:11: note:                 'constexpr fsm::priv::priv(const fsm::priv&)'
C:/dev/test-cpp/components/fsm/include/priv.hpp:11:9: note:                 'fsm::priv::priv(const int&)'
   11 |         priv(const notices&);
      |         ^~~~
C:/dev/test-cpp/components/fsm/include/priv.hpp:8:11: note: 'class fsm::priv' defined here
    8 |     class priv
      |           ^~~~
mingw32-make[2]: *** [components\fsm\CMakeFiles\fsm.dir\build.make:76: components/fsm/CMakeFiles/fsm.dir/fsm.cpp.obj] Error 1
mingw32-make[1]: *** [CMakeFiles\Makefile2:897: components/fsm/CMakeFiles/fsm.dir/all] Error 2
mingw32-make: *** [Makefile:120: all] Error 2

fsm.cpp:

#include "notices.hpp"
#include "priv.hpp"
#include "states.hpp"
namespace fsm {

    /* definition of class notices */

    notices::notices()
    {
        // reserve as many bits as needed
        states_to_set = new uint32_t[STATE_MAX_STATES / 32 + (STATE_MAX_STATES % 32 > 0)]();
        states_to_clear = new uint32_t[STATE_MAX_STATES / 32 + (STATE_MAX_STATES % 32 > 0)]();
    }

    /* definition of class priv */

    priv::priv(const notices& nos)
    {
        printf("sending out notices to %d", nos.states_to_set, nos.states_to_clear);
    }

}

notices.hpp

#pragma once

#include "priv.hpp"
#include "states.hpp"
#include <cstdint>

namespace fsm{

    class notices
    {
    public:
        notices();

    private:
        friend priv(const notices&);

        uint32_t* states_to_set;
        uint32_t* states_to_clear;
    };

}

priv.hpp

#pragma once

#include "notices.hpp"

namespace fsm {

    class priv
    {
    public:
        priv(const notices&);
    };

}

states.hpp

#pragma once

enum global_states_t {
    STATE_SOME_STATE_A = 0,
    STATE_SOME_STATE_B,
    STATE_MAX_STATES,
};